import time
incomplete_sign =50  #.的数量
print('='*23+'开始下载'+'='*25)
for i in range(incomplete_sign +1):
    completed ="*" *i#表示已完成
    incomplete = "."* (incomplete_sign-i) #表示未完成
    percentage =(i /incomplete_sign)*100 #百分比
    print("\r{: .0f}%[{}{}]".format(percentage,completed,
incomplete), end="")
    time.sleep(0.5)
print("\n"+'='*23+'下载完成'+'='*25)